burrill



E. F. BURRILL.

AERIAL APPARATUS on FLYING MACHINE.

APPLICATION FILED DEC, 4,1919.

Patented Nov. 15, 1921.

3 SHEETS-SHEET I.

E. F. BURRILL.

AERIAL APPARATUS 0R FLYING MACHINE.

APPLICATION FILED DEC. 4, 1919- 1,:397,4b0, Patented Nov. 15, 1921.

3 SHEETS-SHEET 2.

FIG M w INVEN TOR.

A TTORNEYS.

E. F. BURRILL.

AERIAL APPARATUS 0R FLYING MACHINE.-

A P P L l C A T l O N F l L E D D E C 4 1 9 l 9.

1,397,400, A Patnted Nov. 15, 1921.

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.UNITED STATES PATENT OFFICE.

ELVYN FREMONT BURRILL, 0F BERKELEY, CALIFORNIA.

AERIAL APPARATUS OR FLY ING-MAGHINE.

Application filed December 4, 1919. Serial No. 342,567.

To all whom it may concern:

Be it known that I, ELvYN FREMONT BUR- RILL, a citizen of the United States, residing at Berkele in the county of Alameda and State of California, have invented a new and useful Aerial Apparatus or F lying-Machine, of which the following is a specification.

My invention relates to aerial apparatus or flying machines and particularly to aerial propellers.

The object of my invention is, in general, to evolve, design and provide a novel type of aerial propeller which shall have, in the first instance, increased thrusting capacity in relation to horse power consumed; in the second instance, shall have the magnitude and direction of its thrust variable and controllable, within certain limits, at will; and in the third instance, shall be immune from certain unavoidable defects inherent in types of propellers at present in use; such new type of propeller being generally adapted to drive aircraft, whether as auxiliary to dirigible balloons or to aeroplanes.

A further object is to provide a novel type of flying machine which, on account pf being driven by my more powerful propeller, shall be competent to fly vertically as well as horizontally; and which, on account of the magnitudinal and directional variability and controllability of thrust, shall enable the operator, at all times, to control the direction of flight from horizontal to vertical or the reverse, at will; and to control the speed of horizontal or vertical flight from zero to maximum; the said zero speed being the same as stationary or hovering flight.

Since, therefore, my invention proposes an extension in the whole scope of flying, it will be necessary, before I proceed to a detailed description of its mechanism, to set forth certain dynamic principles upon which it is based, in order, firstly, that the. inadequacy, for my purposes, of present types of propellers may appear; secondly, that the adequacy, as well as the general nature and operation of my new type of propeller may emerge; and thirdly, that the detailed description may be more clearly understood in the light of the principles.

I shall, therefore, have recourse to the well known formula for pressure in relation to area and velocity, viz,-P:lcAV and its associated formula, (it) varies as angle (6).

Since the factor (70) in the formula varies as the angle of incidence, (0), and reaches maximum value when 6:90 it immedi' ately appears that the common rotary fan or blower, having flat or slightly curved vanes, striking the air broad side on, is the most powerful accelerator possible under the formula; and conversely, that all other,

On the contrary, in the case of the rotary fan'accelerator above referred to, it is clear that its tangential thrust may be increased to any desired extent by increasing the A factor in an axial direction, without involving the velocity factor, and without geometrical increase in horse power; thus main taining at all stages of increase in thrust, constant and maxium efficiency.

For these reasons, and since I employ tangential thrusts as the major thrusts in my propelling system, I make use of a greatly elongated form of the tangential rotary blower, or accelerator above referred to, divided into convenient unit lengths, and in combination with suitable auxiliary elements, as the accelerating or thrust gener-' ating element of my propeller.

My proposed system is further intimately bound up with the well known principle relating to aeroplanes, viz,that the motion But, most serious whereby an aeroplane is sustained in the air is relative motion; so that it is indifferent whether the aeroplane is moving with a velocity through still air or a wind of equal velocity. is sweeping past the stationary aeroplane,

It is at this critical point whence the basic combination of my invention takes its rise.

By means of an operating model of the invention I am able to establish the following new corollary of the above stated principle; namely, that it is immaterial whether the blast whereby a biplane is sustained in stationary or vertical flight is a natural wind or is generated and directed artificially on board the biplane.

Pursuant to the foregoing corollary, I shall now show how I combine the hereinbefore explained rotary accelerator with a biplane to produce a new and useful result.

I employ as the second element of the combination, a structure which is, in essence, a modified biplane having deeply cambered planes. Its fore-and-aft and vertical dimensions should be nearly equal, so that its cross section will form substantially a square. Midway between the planes, I mount the elongated rotary accelerator so that its'axis coincides with the straight line through the centers of the cross sectional squares. The accelerator is provided with a pair of radially opposite vanes, or wings, flat or slightly forward curved, of axial length substantially equal to the length of the planes of the biplane, and of as great radial width as can be rotated between the planes.

Since the portion of the width near the axis has small dynamic value, it may be dispensed with.

In order that the maximum result may be attained, the rear edge of the'upper plane of the biplane should be carried backward and downward in a cylindroidal curve, so as to collect all the dispersed instantaneous upward tending and upper-horizontally tending tangential thrusts about the accelerator and to turn said accumulated thrusts into a downward direction.

Also the lower plane should be strongly cambered and set in a position in relation to the accelerator so that the blast from the accelerator will strike the upper cambered surface at substantially the same angle as in the caseof an aeroplane in normal flight.

The novel behavior of the air within and about the system is approximately represented by the accompanying dynamic graph, plotted from observation of numerous signal ribbons posted at distinctive points about an operating model.

In the diagram, (at), (a), represent an instantaneous position of the vanes, and the circular shading represents the phantasm of the rotating accelerator, and the various air movements are indicated by the arrows.

The air enters at the region of least resistance about the center, and is accelerated by centrifugal force toward the circumference asshown by the cycloidal arrows.

The heavy arrows about the periphery indicate a cyclindrical shell of condensed air pressing upward against the upper plane, and the stream issuing from under the plane exerts a further lifting force by impinging upon the stationary outer air.

It will be seen from the whirling arrows above the lower plane that there is a powerful vacuum in that region, and a consequent negative pressure beneath, as shown by the short arrows. These phenomena are accompanied by a downward tending stream sweeping beneath the plane and joining at the trailing edge a similar stream from above.

It is, therefore, manifest that the upper plane acts as a collector and transformer of the positive or direct thrusts of the accelerator, and so may properly be designated as the positive collector plane; while the lower plane, which is the passive agent of the negative thrusts, may be designated as the negative collector plane; and accordingly these planes will be so designated respectively in the claims.

When now the system is properly equilibrized and the accelerator is rotated in the direction of the arrows, thereensues the following result:

The whole system is lifted and sustained in the air in stationary or vertical flight, with a force which is roughly equal to the lift acquired by a biplane of like area when flying in still air with a translational velocity such that the products of the volumes and velocities of downward-accelerated air are equal in the two systems, in which case the horse powers will also be equal.

Since a single system of this character has a tendency to rotate backward under the influence of the accelerator, I combine two such systems, back to back, in a coupled or opposed system whose resultant tangential thrust is wholly vertical.

While for the sake of simplicity I have shown but a single pair of vanes, I do not thus limit myself, since it is obvious that a greater number, especially four, will yield a still larger result.

Having thus provided a thrusting mechanism adequate for vertical flight, it is obvious that I can multiply its thrusting capacity to any desired extent by employing multiple units, set end to end and axially alined; whence it follows that the forward flight of the system would be endwise like a dirigible balloon.

. In order to provide a thrust for forward flight of the system, I give the elongated vanes of the accelerator a slightly helical form, similar to the blades of a lawn mower.

The purpose of giving the helix but slight deviation from a straight line, is in order not to detract greatly from the vertical thrust of the propeller; and while the axial thrust would be small at any single radial element, yet, on account of the great number of such elements, the aggregate thrust would be large.

It will furtherappear that on account of its extremely long pitch, such a screw would not lose its thrust at high translational velocities of the total system, as is the case with screws of short pitch.

Inasmuch, however, as the propeller is effective for vertical flight without axial thrust, 1 shall claim it even when the helical edge does not deviate at all from the straight line which is in its natural limit.

Having now indicated the underlying principles and the general character of my invention, I will set forth its mechanism, including such further devices as are designed to render it more effective The invention consists of the parts and construction and combination of parts as are hereinafter more fully described and claimed, having reference to the accompanying drawings, in which Figure I is a side view of a unit length of the propeller having slightly helical vanes.

Fig. I is a side view of same showing fan with strai ht vanes.

Fig. 11 is an end view of the propeller and auxiliary mechanism as assembled in a complete machine.

Fig. 111 is a plan view of a complete ma chine consisting of three units, with the upper plane removed from one side in order to show the parts beneath.

Fig. IV is a diagram showing air streams in an operating model, plotted from observa tions of ribbons.

Like numbers in the different views refer to like parts.

Referring to Figs. 11 and 111, (1) is the platform or basic member of the framework, from which branch the various arms, (2), (2), (2), of a transverse frame, which is preferably constructed of bicycle tubing disposed in a triangulated scheme as shown.

The number of such transverse frames exceeds by one the number of units in the system.

Upon the ends of the principal beam of the frame are fixed bearing journals, (3), (3), containing roller bearings for the pivots, (4), (4), of the axles, (5), of the rotary accelerator having end pulleys, (6), (6), and radial arms, (7), (7), which support and carry the vanes, or wings, (8), (8), preferably made of hardened sheet aluminum.

Constructed integrally with the general framework, curved tapering frames, (9), preferably of bent wood, support the positive collector plane, (10), with which is rigidly coupled its cooperating negative col lector plane, (11). The collector planes are preferably made of hardened sheet aluminum, and are riveted to their frames with the rivets, (12).

Referring now to the drivin mechanism, (13), (13) are cylinders of the twin engines, the right hand units of which drive the right hand accelerator clockwise, and the left hand units drive the left hand. accelerator anticlockwise. The parallel crank shafts (14), (1 1), of the twin engines, are synchronized by the cooperating spur gears (15), (15). The driving sprockets (16), (16), of the crank shafts, engage by means of sprocket chains (17), (17), with the pulleys (6), (6), of the accelerators.

A method of controlling the magnitude of the tangential thrust, which I prefer to employ, is as follows:

The upper plane is extended downward and terminates in the flexible flaps (18), (18), which form one wall or guide plane of the air vent at the rear of the lower or negative plane. According as the flap is made to take the position shown by the solid lines, or the position shown by the dotted lines, or any intermediate position, the air vent may be opened to its maximum capacit or partially or wholly closed. By this operation the participation of the lower or negative plane is partially or wholly cut off by infinitesimal degrees, thus effecting a sufficiently large variability in the; magnitude of the lift for attaining rising, falling, or stationary flight.

The necessary movements may be imparted to the flaps by a system of cables attached to a control wheel; which system is well known and therefore need not be illustrated.

Since the mechanism as thus far described, when set in operation, will have a simultaneously vertical and horizontal motion, and since it will often be desirable to secure a purely vertical motion, this may be attained by imparting to the forward end of the apparatus a slight rising lead, until the deviation of the helix from parallelism with the axis is rectified, thus nullifying the forward thrust and rendering the resultant of the vertical and horizontal thrusts purely vertical; and when the desired altitude has been attained, the horizontal thrust may be restored by bringing the apparatus back to trim or even keel. This effect may be attained by slitting the flaps at the inner ends of the fore and aft units, and making the fore and aft flaps (18) separately controllable, thus rendering the variability local as well as general.

lVell known landing devices may be attached to the base of the apparatus, either in the form of buffers or pontoons, mounted upon swinging brackets so as to be folded under the base during flight, and swung out into operative position by means of controlling levers when the apparatus is about to land.

It is evident the apparatus as above described may have various applications.

In one case, a pair of opposed units, equipped with power and controls, may constitute a complete flying machine in itself.

In a second case, a line of units might be constructed on either side of a dirigible balloon, in rotatable opposition, participating to a sufficient degree in the total lift, so as to provide more facile vertical control as well as greater power of horizontal propulsion than is at present the case.

Having'thus described my invention, What i claim and desire to secure by Letters Patent is 1. In an aerial apparatus, or flying machine, propelling means comprising a pair of vertically nd oppositely rotating tangential fans, or acrelerators; positive collector or guide planes, cylindroidal in shape, placed above and about said accelerators, adapted to collect the dis ersed upward tending and upper-horizontally tending tangential streams and to turn said streams into a downward direction; and negative collector or guide planes, cylindroidal in s iape, placed below said accelerators, having their curves inverse to the circles of rotation of the fans, adapted to receive the negative upward thrusts generated beneath them by the partial vacuums above, and to turn the lower-horizontally tending streams into a downward direction; all substantially as specified.

2. in an i rial apparatus or flying maa chine, propelling means comprising a palr of vertically and oppositely rotating fans, or accelerators; the vanes of said fans or accelerators having a small degree of helical curve; positive collector or guide planes, cylindroidal in shape, placed above and about said accelerators, adapted to collect the dispersed upward tending and upper-horizontally tending air streams and to turn said streams into downward direction; and negative collector or guide planes, cylindroidal in shape, placed below said accelerators, having their curves inverse to the circles of rotation 01"" the accelerators and adapted to receive the negative upward thrusts generated beneath them by the partial vacuums above, and to turn the lowerhorizontaily tending streams into a clownward direction, substantially as specified.

in an aerial apparatus, or flying machine, the combination of propelling means comprising a pair of vertically and oppositely rotating fans or accelerators; positive collector planes, cylindroidal in shape, placed above and about said accelerators; negative collector planes, oylindroidal in shape,- placed below said accelerators, with their curves inverse to the circles of rotation of the fans; and means for controlling the magnitude of the thrust, substantially as specified.

In an aerial apparatus or flying machine, the combination of a series of propel- .ler units, each of the character set forth in claim 3, axially alincd and cooperating cumulatively, and means for so controlling the direction of their combined thrusts as to annul the forward component of the thrust and secure a purely vertical thrust, or vice versa, substantially as specified.

ELVYN FREMGNT BURRILL 

